- Docket Number
- 110 MW
- Sonoma County
- Steam Turbine
- Project Status
- Operational (Geothermal)
- Project Type
- Application for Certification
The Quicksilver Geothermal Project (Unit 16) is in Lake County near the Sonoma County line, in the Geysers Known Geothermal Resource Area along the ridgeline of the Mayacamas Mountains with moderately steep terrain, approximately 15 miles west of the town of Cobb. Unit 16, originally known as Pacific Gas & Electric Company’s (PG&E) Geysers Unit 16 Geothermal Project was certified by the California Energy Commission (CEC) in September 1981. Commercial operation began in October 1985.
The dry-steam geothermal plant was approved for up to 110-megawatts; however, due to reduced steam pressures, the plant supplies about 53-megawatts of base-load electricity to northern California's power grid. Major structures include a turbine building, cooling tower, electrical switchyard, and a hydrogen sulfide (H2S) abatement facility. The turbine building houses the steam turbine generator and other associated equipment required for electrical power production. The mechanical draft cooling tower dissipates heat from the power cycle. Hydrogen Sulfide (H2S) emissions are abated using a surface condenser/Stretford process which partitions the H2S into gaseous and condensate (liquid) forms.
In April 1999, the California Energy Commission granted a transfer of ownership of Quicksilver Geothermal (Unit 16), the former PG&E Geysers Unit 16 Geothermal Project to Geysers Power Company, LLC, a wholly owned subsidiary of the Calpine Corporation.
Power Plant Certification and Exemption Processes
As required by the Warren-Alquist Act, the Energy Commission monitors Commission-certified energy projects throughout construction, operation, and closure to ensure compliance with the conditions of certification imposed by the Commission’s Final Decision for approving the projects.